Fabric take-off mechanism for knitting machines



Feb. 18, 1936. P. SCHMIDT 2,030,944

FABRIC TAKE-OFF MECHANISM FOR KNITTING MACHINES Filed Sept. '7, 1932 I 5 Sheets-Sheet l f1r3- l INVENTOR. Paul Scfgmidi,

Feb. 18, 1936. SCHMlDT 2,030,944

FABRIC TAKE-OFF MECHANISM FOR KNITTING MACHINES Filed Sept. 7, 1932 3 Shets-Sheet 2 INVENTOR. Baal Schmidt,

.A TTORNEY.

wg y Feb. 18, 1936. P, H DT 2,030,944

FABRIC TAKE-OFF MECHANISM FR KNITTING MACHINES Filed Sept. '7, 1932 5 SheetsSheet 5 I1 E E1 54 5i 5 1 5 L I l 1 J I N VEN TOR. Papal Schmidt,

ATTORNEY.

Patented Feb. 18, 1936 UNITED STATES PATENT OFFICE FABRIC TAKE-OFF MECHANISM FOR KNITTING MACHINES Application September '1, 1932, Serial No. 631,976

16 Claims.

This invention relates to improvements in knitting machines, and more particularly to the fabric take-off mechanismtherefor.

One object of the invention is to provide novel and improved take-oif-tension regulating mechanism which maintains constant the tension applied to the fabric being knitted, or reciprocatively moves the fabric, in accordance with movement of the knitting needles toward or away from the fabric take-ofi means, and which will have a smooth, positive action at all times in such manner as to prevent vibratory or jerking effects upon the fabric, and to prevent overtravel or backlash of the take-ofi means, particularly at the times of application thereto, or release therefrom, of the tension regulating mechanism.

A further object is the provision of take-01f tension regulating mechanism which operates, upon movement of the needles toward or away 20 from the fabric take-off means, substantially instantaneously to vary the tension exerted thereby on the fabric, regardless of the position of the take-off means, and which is effectivefor minute movements of the needles.

Another object is to provide tension regulating mechanism having clutch members one of which also acts as a brake on the take-off means to eliminate jerking or backlash on the fabric; the clutch members are adapted to instantly engage from any position of disengagement, and

are adjustable to enable any desired degree of tension to be maintained on the fabric, or to compensate for wear of parts in use, and the time of application, or the'time of release, of the tension regulating mechanism may be accurately adjusted.

The invention comprises the novel elements, features of construction and arrangement of parts in cooperative relationship as herein set forth by the following detailed description and accompanying drawings of one embodiment thereof, reference to which will make the above and other objects and attendant advantages readily apparent.

Those parts of astraight knitting machine which come more particularly into consideration in connection with this invention are shown in the accompanying drawings, in which: j

Figure 1 is a partial front elevational view of one section of a knitting machine embodying-the invention;

Fig. 2 is a view, parts in section, taken on the line 2-2 ofFig. 1 and looking in the direction of the arrows; I

Fig. 3 is an enlarged plan view of certain parts of the tension regulating mechanism;

Fig. 4 is an enlarged side view of certain parts of the mechanism;

Fig. 5 is a view, parts in section, taken on the line 55 of Fig. 3 and showing the mechanism in one position of operation; and

Fig. 6 is a fragmentary plan view, taken on the line 66of Fig. 2, showing certain parts of the mechanism in one operating position.

Referring to Figs. 1 and 2, the novel tension regulating mechanism is shown in operative relation with one knitting section of a fullfashioned knitting machine of the type generally known in the art as the Reading machine, the various parts and operation of which are well known and are therefore not described here in detail. The knitting section shown comprises two half sections having sets of knitting needles I mounted in a needle bar 8. The needles require both. vertical and horizontal movement to draw the newly formed loops of the fabric through the old loops and to press the free ends of the needle beards into grooves of the needles so as to form a closed eye in order that the old l5 which cooperates with a cam IS on machine cam shaft H. The members above described provide for periodic reciprocation of the needle bar in a horizontal direction, forwardly and rearwardly.

Pivotally secured at I8 to a needle bar bracket I9 is a needle bar lifting arm 20 clamped at one end to a rock shaft 2|; a needle lever 22, which is also clamped at one end to the rock shaft, forms with arm 29 a lever fulcrumed on shaft 2|, and provided with a cam roller 23 which cooperates with a rotary caiii 24on cam shaft I! to periodically move the needle bar in a vertical direction. Anchored springs 6i and 62 connected to the lower extremities of presser lever l3 and needle lever 22, respectively, normally bias the cam rollers l5 and 23 into contact with the cams l6 and 24.

The fabric take-off device comprises a rotary shaft 25 which is operated in the well known manner by a weight (not shown) connected thereto 7 by a. rope, and on which as many fabric take-01f rollers 26'are secured as there are needle bars; fabric attaching means being generally connected 60 shaft Cams |6 and 56are of the same genwith each take-off roller in theform of straps 21 provided with a welt bar, in the case of a legger, at their outer ends adapted to engage the welt 26 of the stocking fabric of web 29.

During the knitting process the weight rotates shaft 25 and take-01f roller 26 in a clockwise dimember or hardened steel roller 3|, having two i shoulders 32 of smaller diameter, is keyed to the reel shaft 26. Two rocking beam members 33, more clearly shown in the plan view of Fig. 3, are rotatably mounted on the shoulders 32, the rocking beam members being held in fixed parallel relation with respect to each other by stud bolts 34. Positioned between the ends of the rocking beam members, and rotatably mounted on the stud bolts 34, are two oppositely disposed clutch memsbers 35 and 36 the inner ends ofwhich have tapered surfaces 35a and 36a adapted, upon rota-v tion of the members in opposite directions respectively about the stud bolts 34, to clutch and lock the circular member 3| in wedg'ing engagement therewith. The outer ends of the clutch members '35 and'36 are pivotally connected to fork heads 31 and 38 adjustably secured by collars 39 and set screws 36a to operating rods 46 and 4|, respec- .tively.

pperating rod 4| is pivotally connected to bellcrank lever 42 by means of a stud 43 adjustable within a slot (indicated bydotted lines) in boss 44 on the bell crank lever. A tension spring 45, Fig. .4, connected at one end to a collar 46 on rod 4| and at its other end to an ear 41 on one of the rocking beam members 33, is preferably, although not necessarily, employed to insure uniform and smooth release of the clutch members at the proper time during downward movement of operating rod 4|." I Operating rod 46 is surrounded by a helical compression spring 46 pressing at its upper end against the collar 39, and at its lower end against a shoulder portion49of stud-56 pivotally secured to bell crank lever 42. The lower end of rod 46 extends through, and is reciprocable within, a bore through shoulder 46 of pivotally mounted stud 56, the rod having an adjustable collar 5| for limiting its upward travel.

V The bell-crank lever 42 is journaled at 52, Figs; 1 and 2, to frame member 53, and has a cam follower or roller 54 normally biased by spring 55 into engagement with a rotary cam 56 on cam eral configuration; as already .mentioned, cam

direction, and similar or vertical movement is imparted by cam 56, through roller 54 and bell crank lever 42, to operating rods 46 and 4 i, which movement brings the clutch members 35 and 36 into engagement with clutch member 3| in the following manner: Upon movement of the needles in a direction away from .the take-0E reel 26, bell crank lever 42 is rotated in a counter-clockwise direction, as viewed in Figs. 2, 4 and 5, thus moving operating rod 4| upwardly and rotating clutch member 36 in a counter-clockwise 'direcor wedging engagement with roller member 3| which at this time is rotating, in a clockwise direction due to the tension normally exerted on the take-off reel, by the weight hereinbefore mentioned. At the instant of clutching engagement between the members 3| and 36, the rotation of the take-off reel 26 and roller 3| relative to the rocking beam members 33 is stopped, and the continued upward movement of rod 4| causes the entire rocking beam assembly to rotate in a counter-clockwise direction about the shaft 25 as an axis, carrying with it the take-off reel 25- so that the reel now rotates in a reverse direction. The rotation of the bell crank lever and upward movement of the rod 4| continue during movement of the needles in a direction away from the take-01f reel, thus preventing increase in the tension or strain formerly exerted on the fabric, and causing the fabric to move in the same di-' member 35 in a clockwise direction so that its tapered surface 35a rolls into engagement with roller 3|. Member 35 acts to prevent rotation of roller 3| in an opposite direction with respect to the action of member 36, so that the two members 35 and 36 coact to lock roller 3| against rotation in either direction with respect to the rocking beam assembly, and thus prevent oscillating or jerking movement of the take-oi! reel, or overrlmning of the reel in reverse direction, during application of the tension regulating mechanism. Continued movement of ball crank lever 42 and rotation of the rocking beam assembly cause further compression of spring 46 and further'ex- .tension of the lower end of rod 46 through the shoulder 46 of stud 56. v

Reverse movement of the needles, i. e... in a direction towards the take-off reel, causes reverse movement of the bell crank lever '42 and downward movement of operating rod 4|, with con-' sequent rotation of the'rocking' beam assembly andtake-off reel in clockwise direction, the

springs 45 and 46 causing the rocking beam as-Y sembly to rotate with movement of the rod 4|.

Upon return of the needles to normal position with respect to the fabric take-off reel, an adjustable stop 56 on one ofthe rocking beam.

members 33 engages an arm 53a'of frame member 53. This stops further rotation of the rock- 'ing beam assembly, and the slight remaining travel of the operating rods causes release of the clutch members, so that the tension applied to the fabric is again controlled'by the weightacting through the tension take-off l6 reciprocates the needle bar 6 in a horizontal exerted by spring-46, however, substantial pressure is exerted between surface 35:: and the adjoining contacting surface of roller 3| while the clutchmember 351s in engagement therewith.

The clutch member therefore acts as a'friction '05 in the opposite direction. Due to the pressure brake on the roller 3| during rotation of the rocking beam assembly in a clockwise direction,

V and the travel of rod 46 is preferably, although tion,itstapered surface 364 rolling into clutching not necessarily, adjusted so that this braking 16 member 36. The braking action of member 35.

minimizes or prevents jerking or back lash efiects on the fabric caused by reversal'of rotation of the rocking beam assembly, or due to release of the clutch 36. If desired, however, clutch 35 may be adjusted to release simultaneously with release of clutch 36.

The effective lengths of the operating rods and travel of the clutch elements may be adjusted to any desired degree of sensitivity, and to compensate for last motion or wear on the parts, so that the regulating mechanism will cause the tension exerted on the fabric by the take-off reel to be varied, upon movement of the needles, to instantly compensate for such movement, and move the fabric in accordance with the needle movement, so that constant uniform tension is maintained on the fabric during the needle reciprocations.

The clutch members 3| and 36 permit a very small clearance, of the order of 1/1000 of an inch,

to be maintained between them while in disengaged position, and the clutch members are adapted to engage or disengage in any position relative to each other, and therefore very small movements of the needles will cause engagement or disengagement of the clutch members to accurately regulate the tension applied to the fabric, and substantially instantaneously with movement of the needles. It will be understood that in speaking of varying the tension exerted on the fabric by the take-off real, this means variation of the tension which would be applied to the fabric if the reciprocating movement of the needles were not compensated for by the tension regulating mechanism in a manner to maintain uniform tension on the fabric.

During the narrowing operation of the knitting machine, the fabric 29 must be slackened to relieve the loop pull so as to facilitate shifting of desired loops to adjacent'needles, in a manner well understood in the art, and in order to put the narrowing mechanism into operation the cam shaft 17 is shifted to the right in Fig. 1. This action causes a cam follower or roller 59 (which, as more clearly shown in the plan view of Fig. 6, is disengaged in the position of Fig. 1) to engage cam 60 on cam shaft H, which provides suitable additional motion to the lever 42 and operating rods 69 and 4| to bring about the desired slack in the fabric 29, without changing its cyclic. reciprocative movement with respect to the needles I. A view of the contour of cam 60 is shown in Fig. 2; the roller 59 is omitted in this view more clearly to show the other cam members. In .the narrowing operation, the needle bar 8 remains at rest to facilitate loop transfer by the usual transfor points, and the tension regulating mechanism causes reverse rotation of the fabric take-ofi' reel to provide the desired slack for the loop transfers, the cam roller 54 preferably being disengaged and inoperative during this operation. Re-

with.

The illustrative embodiment specifically shown and described may obviously be further changed,

modified and applied in various ways without departing from the invention herein disclosed and claimed.

I claim: 1. In a knitting machine, a reciprocatively operated set 'of needles for producing a knitted fabric, tension take-off means for the fabric, and means for controlling the movement of said takeoff means to compensate for the reciprocating movement of the needles, comprising overrunning clutch structure actuated in accordance with movement of the needles, saidstructure acting as a clutch on said take-off means to relieve tension on the fabric in one direction of movement of the take-off means and exerting a braking action on the take-off means in the opposite direction of movement thereof.

2. In a knitting machine, a reciprocatively operated set of needles for producing a knitted fabric, fabric take-off means, a member rotating in correspondence with movement of said take-off means, and means for controlling the movement of said take-off means to compensate for reciprocating movement of the needles, comprising a clutch member having a tapered cam like surface positioned adjacent said rotating member and movable into direct wedging engagement with a surface of the rotating member upon movement of said needles in a predetermined direction, and means for positively moving said clutch member in both clutching and releasing directions, and brake means acting on said' rotating member upon the release of said clutch member.

3. In a knitting machine, a reciprocatively operated set of needles for producing a knitted fabric, fabric take-off means, a member rotating in correspondence with movement of said take-off means, and means for contro'ling the movement I- of said take-off means to compensate for reciproeating movement of the needles, comprising a plurality of pivotally mounted clutch members rotatable into engagement with said rotating member upon movement of the needles in a predetermined direction, said clutch members simultaneously acting in opposite directions, respectively, to prevent rotation of said memberin either direction with respect to the clutch members.

4. In a knitting machine, a reciprocatively operated set of needles for producing a knitted fabric, fabric take-off means, a member rotating operated set of needles for producing a knitted fabric, fabric take-off means, a member rotating in correspondence with movement of said takeoff means, and means for controlling the movement of said take-01f means to compensate for reciprocating movement of the needles, comprise ing a plurality of members angularly spaced about said rotating member and adapted to be simultaneously rotated in opposite directions;

respectively, into clutch engagement with said rotating member.

6. In a knitting machine, a reciprocatively operable set of needles for producing a knitted fabric, rotatable take-off means for the fabric, a member adapted to. be rotated in correspondence with'the take-off means, and means for controlling the movement of said take-01f means to compensate for reciprocating movement of the needles, comprising a pivotally mounted clutch member positioned adjacent to said rotatable member, and having a tapered cam-like surface adapted to be moved into direct clutching engagement with the rotatable member for opposing the tension exerted by said take-off means upon movement OfiSflid needfes in a predetermined,

prising an actuating element and a member, pivotally secured thereto and rotatable into direct clutching engagement with said rotating member.- for opposing the tension exerted by said take-ofi means upon -movement of saidt needesiin a pre-- determined direction, and means acting upon the disengagement of the pivoted member, adapted to further control the action of the take-01f means. e

8. In a knitting machine, a reciprocatively operated set of needles for producing a knitted fabric, fabric take-off means, a member rotating in correspondence with movement of said take-off means, and means for controlling the movement of said take-off means to compensate for reciprocating movement of the needles, comprising a clutch actuating element, a clutch member secured to said element and having a tapered camlike surface positioned adjacent said rotating member and rotatable into direct clutching engagement with a surface of the rotating member upon movement-of said needles in a predetermined direction, and means for positively moving said clutch-member into both clutching and releasing positions, and brake means acting on said rotating member upon the reease of'saidl clutch member.

9-. In a knitting machine, a. reciprocatively operated set of needles for producing a knitted fabric, fabric take-elf means, a member rotating in correspondence with movement of said take-off means, and means for controlling the movement of said take-off means to compensate for reciprocating movement of the needles, comprising a rotatable clutch member having a'surface eccenric, a fabric take-off device for operation bymeans moving it in a given direction, tension means for imparting movement to said take-off device in one direction, and tension controlling means for imparting a reverse movement to said take-off device, said tension controlling means comprising an element connected to the take-ofi device, a pivotal lever, and means for locking the lever to said element for preventing overtravel of the take-off roll in said reverse direction.

11. In a knitting machine, a reciprocatively operated set of needles for producing a knitted fabric, fabric take-off means including a clutch element rotating in accordance with movement of said take-off means, and means for controlling the movement of said take-off means to compensate for reciprocatory movement of the needles, comprising a rotatable member, a plurality of clutch elements carried by said ro atable member and angularly spaced about .he axis of said member, and means for actuating the rotatable member, said fmeans simultaneously actuating the clutch elements carried by said rotatable member into clutching engagement with a surface of the first named clutch element, thereby causing said rotatable member to actuate said take-off means in a direction to vary the tension exerted thereby on the fabric.

12. In a knitting machine, a reciprocatively jjoperated set of needles for producing a knitted fabric, fabric take-off means, a member rotating in correspondence with movement of said takeoff means, and means for controlling the movement l'of said take-oif neans as compensate for reciprocating movement of the needles, comprising a rocking lever carrying an eccentric clutch member, and means for positively actuating said eccentric clutch member into direct clutching engagement with a surface of said rotating takeof! member and for causingthe rocking beam to rotate said takeoff member to vary the tension exerted, on the fabric by said take-ofi means,

said actuating means also positively actuating said eccentric clutch member to release it from said rotating take-off member and to operate means controlling the subsequent action of the in correspondence with movement of said takeofi means, and means for controlling the move ment of said take-01f meansto compensate for reciprocating movement of the needles, comprising a rocking beam. pivotally mounted clutch members carried thereby and adaptedto act in opposite directions relative to movement of said rotating take-off member, and means for actuating said clutch members into clutching engagement with said rotating member and for causing the rocking beam to rotate said take-off member to control the tension exerted on'the fabric by said take=ofi means.

14. In combination, in a straight knitting machine, cam means including a shaft for operating needles and a clutch, a needle bar, a take-off reel,

a circular clutch element of said clutch coaxially fixed to the reel, a walking beam pivotally coaxial with the reel, clutch members pivoted at the ends of the beam having eccentric-cam clutch faces for cooperation with the periphery of the circular clutch element, a'lever carrying a follower for clutch-operating cam of said cam means and having a link-receiving end, a member pivoted on said cam follower lever and having an aperture, a link pivotally connected to one of said pivoted clutch members and to the cam follower lever at one of a selective plura ity of positions on said receiving end, a link pivotally connected to the other pivoted clutch member and extending through said aperture, and a compression spring surrounding said second link and acting between the link and the apertured member.

15. In combination, in a straight knitting machine, cam means including a shaft for operating needles and a clutch. a needle bar, a take-01f reel,

a cylindrical clutch member of said clutch coaxiaily fixed to the reel, a lever having portions pivotally coaxial withthe reel at opposite sides of said member, a clutch element pivoted between said opposite-side lever portions having an eccentric-cam clutch face for engagement with the periphery of said member and a portion radially outwardly from the axis of said cylindrical member beyond the outer ends of said lever portions, a lever carrying a follower for a clutch operating cam of said cam means and having a link-receiving end, and a link pivotally connected to said radially-outward portion of said pivoted clutch element and to the camfollower lever at one of a selective plurality or positions on said receiving rod.

16. In a knitting machine, a reciprocativelyoperated set of needles for producing a knitted fabric, take-off means for the fabric including a portion for engagement with the fabric and a rotatable clutch element for connection to said fabric-engaging portion, and means for controlling movement of the "clutch element comprising an oscillatory beam pivotally movable about an axis between its ends coincident with against and from the rotatable clutch element, 7

a pair of links pivoted at corresponding ends one to each of said pivoted clutch members, a pivotal actuating arm for said links, one of said links having adjacent to its other end a pivotal connection to said arm adjacent to the free end of the latter, said connection being adjustable along the arm, the other link having adjacent to its other end a longitudinally-slidable connection to the arm between the pivot axis and the free end of the arm, a compression spring about the latter link between the arm and the link, and a tension spring between the oscillatory beam and the other link.

' PAUL SCHMIDT. 

